1. Field of the Invention
This invention relates to electrostatic field measurement devices and, more specifically to an electrostatic field measurement device that determines the position and location of item(s) under study with respect to the location of the measurement device, by actively inducing, and then measuring the corresponding electrostatic response, both magnitude and direction (vector), of item(s) under study, within the field of view of the measurement device. The field of view of the device is within a three dimensional space surrounding the measurement device. The distance portion of the vector, that represents the sensing capability of the measurement device, is directly correlated to the amount of the electric field developed by the measurement device, and the medium located between the device and the item(s) under study. In addition, the invention seeks an electrostatic field response from item(s) under study that is representative of their overall electrostatic field capacity, and not the electric field representative of just one surface of the item{s} under study.
2. Description of the Related Art
Heretofore, the accuracy of the measurements of the Electric Field (E Field) of items has been restricted by the requirement of the measurement devices to be located very near the item or surface being measured. In addition, it was required to position the sensor using external means. This external positioning was performed in a specific manner, to increase the accuracy of the sensor reading of the local E field. See P. E. Secker and J. N. Chubb, Journal of Electrostatics, 16 (1984) 1-19 (Elsevier Science Publishers B. V., Amsterdam; and W. E. Vosteen, A Review of Current Electrostatic Measurement Techniques and Their Limitations, Paper presented at the Electrical Overstress Exposition, Apr. 24-26, 1984, San Jose, Calif.
The literature on measuring the Electric field also focuses on using a passive means for the collection of E field data. The IEFS concept is based on using an active means for E field data collection.
Initially it appears that the IEFS should fall into Class 324. However, a review of patents in this class reveals that the concept of actively inducing an external E Field, that forces a corresponding E Field response from Item(s) Under Study (IUS), has not been addressed in the Patent literature to date. All sensor concepts in this class are based on a passive collection of E field data, that corresponds to the peculiar characteristics of the IUS. This results in the established set of sensors, represented in Class 324, detecting the E field data on one surface of the IUS. It can then be inferred that a similar amount of E field information would be detected on the remaining surfaces of the IUS, if the sensor would be presented on the corresponding remaining surfaces.
The IEFS uses a different concept. It presents a known level of E field energy within a range that the E field of the IUS can detect. The IUS subsequently responds to this induced field with its own E field of opposite polarity, in a manner proportional to the energy levels of the induced E field. The IEFS E field (the parameters which are already known), responds to the IUS's E field response by allowing its own E field to move around the IEFS surface. This movement of the E field around the surface of the IEFS, results in a concentration of E field energy density at the location closest to the IUS, and at an energy level that is proportional to the IUS's E field response. Sensing the amount and rate of change of the IEFS E field, at specific locations around the surface of the IEFS, is used to infer specific characteristics that are attributed to the IUS, based on the detected pattern of the E field surrounding the IEFS. These characteristics include location identification of the IUS with respect to the IEFS, as well as determining the change in respective locations over time. These characteristics also provide information that is used to record E field information that is unique to a particular IUS.
The IEFS concept allows E field readings to be made on an IUS, with high levels of accuracy, at much greater distances between the IEFS sensor and the IUS, when compared to the body of sensors addressed in Class 324.
The current body of sensors in Class 324, that uses radiated means to sense E fields, requires a specific external positioning of the sensor, with respect to the surface of the IUS, in order that accurate and repeatable measurements can be made. The IEFS concept does not require specific external positioning with respect to the IUS. It automatically will make accurate and repeatable measurements of both E field magnitude, and location of the IUS, with respect to the location of the IEFS.
A review of additional patents in Class 324, reveals that a sub-class of measuring sensors/meters focuses on detecting an IUS in the ground through conducted means. The IEFS concept is based on using radiated means to detect IUS. The sensitivity of the IEFS in detecting the IUS, is limited only by the electrical properties of the medium that is located between the IEFS and the IUS.
A review of patents in Class 250, reveals that this class of measuring sensors/meters focuses on detecting free ions as they move through space. This passive concept of detecting free ions differs from the IEFS concept, in that the IEFS concept focuses on detecting changes in its own E field in response to opposing charges presented by the IUS. This action/reaction concept focuses on sensing ions that are within the influence of the two E fields of interest.
A review of patents in Class 33, reveals that this class of measuring sensors/meters focuses on detecting the Magnetic field component of an IUS. The IEFS concept senses the Electric field component of the items that Class 33 items would normally detect.
A review of patents in Class 73, reveals that this class of measuring sensors/meters focuses on detecting the rate and/or direction of ion flow in a passive manner. The IEFS concept senses the presence of ions based on the IUS response using an active (action/reaction) concept.